Roon core and client are both V2.0 Build 1169. Search function worked fine across all devices (PC, android mobile phone and android tablet) until I updated to latest build 1169.
Windows 10 v1511 can’t upgrade .NET Framework to version 4.8. This problem has similar root cause to previous critical issues with no function available in older .NET Framework version as below.
12/10 01:38:33 Critical: [search] error performing instant search: System.MissingMethodException: Method not found: 'System.Collections.Generic.HashSet`1<!!0> System.Linq.Enumerable.ToHashSet(System.Collections.Generic.IEnumerable`1<!!0>)'.
at Sooloos.Broker.Music.SearchApiConverter.BuildApiSearchRequest(LibrarySearchResults librarySearchResults, List`1 playlists, List`1 tags, Library library)
at Sooloos.Broker.Music.LibraryApi.<RunInstantSearch>d__6.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Sooloos.Broker.Music.LibraryApi.<>c__DisplayClass5_0.<<Sooloos-Broker-Api-Library-UnifiedAutocomplete>b__0>d.MoveNext()
I hope next update they will address this issue and resolve Roon Search being broken with workaround solutions from using different implementations for older .NET framework version.